How to use azure cosmos within azure function app?

Question

I am trying to use Microsoft.Azure.Cosmos within azure function app with binding CosmosClient as an input but i am getting error messages and it isn't working.

Can you help me to get it work, please?

Answer 1

@Ashraqat Sheta Thanks for clarifying. I just wrote a sample code that receives an HTTP request and writes the request body to a Cosmos DB container. The function is triggered by an HTTP request and uses the [HttpTrigger] attribute to define the trigger. It uses the cosmosclient to perform the add, update and delete operation:

• You need to create an Azure Function APP project in your Visual Studio with HTTP Trigger.
• Then ensure that you install Microsoft.Azure.Cosmos package via nuget.
• please update the cosmos DB connection details in the code.
• Then you can run the Function app.

using System;
using System.IO;
using System.Threading.Tasks;
using Microsoft.AspNetCore.Mvc;
using Microsoft.Azure.WebJobs;
using Microsoft.Azure.WebJobs.Extensions.Http;
using Microsoft.AspNetCore.Http;
using Microsoft.Extensions.Logging;
using Newtonsoft.Json;
using Microsoft.Azure.Cosmos;
using System.Configuration;

namespace CosmosClientCRUDFuncApp
{
    public static class Function1
    {
        
        [FunctionName("Function1")]
        public static async Task<IActionResult> Run(
            [HttpTrigger(AuthorizationLevel.Function, "get", "post", Route = null)] HttpRequest req,
            ILogger log)
        {
            string requestBody = await new StreamReader(req.Body).ReadToEndAsync();
            dynamic data = JsonConvert.DeserializeObject(requestBody);
            string operation = data?.operation;

            string endpoint = "https://mycosmosdb.documents.azure.com:443/";
            string key = "v3NJKDr7P0pNqt**********************zZwACDbnCNHTw==";
            CosmosClient client = new CosmosClient(endpoint, key);
            string databaseName = "testdb";
            string containerName = "testcontainer";
            Container container = client.GetContainer(databaseName, containerName);

            if (operation == "add")
            {
                string description = data?.description;
                if (description != null)
                {
                    dynamic document = new { Description = description, id = Guid.NewGuid().ToString() };
                    await container.CreateItemAsync(document);
                    log.LogInformation("C# HTTP trigger function processed a request to add a document.");
                    return new OkResult();
                }
                else
                {
                    return new BadRequestObjectResult("Please provide description for adding a document.");
                }
            }
            else if (operation == "update")
            {
                string id = data?.id;
                string description = data?.description;
                if (id != null && description != null)
                {
                    try
                    {
                        ItemResponse<dynamic> response = await container.ReadItemAsync<dynamic>(id, new PartitionKey(id));
                        dynamic document = response.Resource;
                        document.Description = description;
                        await container.ReplaceItemAsync(document, id, new PartitionKey(id));
                        log.LogInformation("C# HTTP trigger function processed a request to update a document.");
                        return new OkResult();
                    }
                    catch (Exception ex)
                    {
                        log.LogError(ex, "Error updating document");
                        return new StatusCodeResult(500);
                    }
                }

               
                else
                {
                    return new BadRequestObjectResult("Please provide both id and description for updating a document.");
                }
            }
            else if (operation == "delete")
            {
                string id =  data?.id; 
                if (id != null) 
                {
                    try
                    {
                        ItemResponse<dynamic> response = await container.DeleteItemAsync<dynamic>(id, new PartitionKey(id));
                        log.LogInformation("C# HTTP trigger function processed a request to delete a document.");
                        return new OkResult();
                    }
                    catch (Exception ex)
                    {
                        log.LogError(ex, "Error deleting document");
                        return new StatusCodeResult(500);
                    }
                } 
                else
                { 
                    return new BadRequestObjectResult("Please provide id for deleting a document."); 
                }
            }
            else 
            {
                return new BadRequestObjectResult("Please provide a valid operation (add, update, or delete)."); 
            }
        }
    }
}

To send an HTTP trigger request to this function app from Postman, you can follow these steps:

• Open Postman and create a new request.
• Set the request method to POST.
• Set the request URL to the URL of your function app. This should be in the format https://localhost:port/api/<function-name>.
• In the request body, select the raw option and set the content type to JSON.
• For the add operation, you can set the request body to:

{
    "operation": "add",
    "description": "This is a test document."
}

{
    "operation": "update",
    "id": "<document-id>",
    "description": "This is an updated test document."
}

• For the delete operation, you can set the request body to:

{
    "operation": "delete",
    "id": "<document-id>"
}

• This should send an HTTP trigger request to your function app and perform the specified operation.

If you have any follow-up questions, please do let me know. I would be happy to help.

** Please do not forget to "Accept the answer” and “up-vote” wherever the information provided helps you, this can be beneficial to other community members.